2,749 research outputs found
Effects of Microbial DNA on Human Forensic DNA Profiles
poster abstractMost biological evidence obtained from crimes scenes is found in non-sterile environments, and therefore there is an opportunity for the forensic samples to become contaminated with environmental DNA. In particular, the effects of microbial species that may contaminate forensic samples have not been extensively studied. This type of information could be especially important in cases where decomposition has occurred and microbes are in abundance. We investigated the environmental effects on DNA samples via contamination from microbial sources by intentionally spiking human DNA samples with known concentrations of DNA from 17 common microbe species associated with human decomposition. Quantitation and amplification was performed using the Quantifiler® Human DNA quantitation kit (Thermo Fisher Scientific, Inc.) and PowerPlex® 16 HS system (Promega Corp.), respectively. Single species of microbial DNA were added in varying quantities (1, 50, 100 ng) to a standard 1 ng human DNA sample. Results indicate that there was little to no effect on quantitation of the human DNA samples. However during genotyping, two species, Bacillus subtilis and Mycobacterium smegmatis, produced an artifact peak at the TPOX locus. The same artifact was still amplified when the DNA of the two species was tested in the absence of human DNA. This type of data will impact the forensic community as it demonstrates that microbial contamination may affect the development and interpretation of a human DNA profile. As most forensic genotyping kits are developed to be human specific, these results indicate that caution should still be used in interpreting the human DNA profile, especially in cases of decomposition in which there would be higher levels of microbial contamination
Potential for measuring the longitudinal and lateral profile of muons in TeV air showers with IACTs
Muons are copiously produced within hadronic extensive air showers (EAS)
occurring in the Earth's atmosphere, and are used by particle air shower
detectors as a means of identifying the primary cosmic ray which initiated the
EAS. Imaging Atmospheric Cherenkov Telescopes (IACTs), designed for the
detection of gamma-ray initiated EAS for the purposes of Very High Energy (VHE)
gamma-ray astronomy, are subject to a considerable background signal due to
hadronic EAS. Although hadronic EAS are typically rejected for gamma-ray
analysis purposes, single muons produced within such showers generate clearly
identifiable signals in IACTs and muon images are routinely retained and used
for calibration purposes. For IACT arrays operating with a stereoscopic
trigger, when a muon triggers one telescope, other telescopes in IACT arrays
usually detect the associated hadronic EAS. We demonstrate for the first time
the potential of IACT arrays for competitive measurements of the muon content
of air showers, their lateral distribution and longitudinal profile of
production slant heights in the TeV energy range. Such information can provide
useful input to hadronic interaction models.Comment: 15 pages, 11 figures, 2 tables, accepted for publication in
Astroparticle Physic
A likelihood method to cross-calibrate air-shower detectors
We present a detailed statistical treatment of the energy calibration of
hybrid air-shower detectors, which combine a surface detector array and a
fluorescence detector, to obtain an unbiased estimate of the calibration curve.
The special features of calibration data from air showers prevent unbiased
results, if a standard least-squares fit is applied to the problem. We develop
a general maximum-likelihood approach, based on the detailed statistical model,
to solve the problem. Our approach was developed for the Pierre Auger
Observatory, but the applied principles are general and can be transferred to
other air-shower experiments, even to the cross-calibration of other
observables. Since our general likelihood function is expensive to compute, we
derive two approximations with significantly smaller computational cost. In the
recent years both have been used to calibrate data of the Pierre Auger
Observatory. We demonstrate that these approximations introduce negligible bias
when they are applied to simulated toy experiments, which mimic realistic
experimental conditions.Comment: 10 pages, 7 figure
Estimation of the number of contributors of theoretical mixture profiles based on allele counting: Does increasing the number of loci increase success rate of estimates?
DNA mixtures are more frequently encountered in casework due to increased kit sensitivity, protocols with increased cycle number, and requests for low copy number DNA samples to be tested. Generally, the first step in mixture interpretation is determining the number of contributors, with the most common approach of maximum allele count. Although there are previous studies regarding the accuracy of this approach, none have evaluated the accuracy with the newly expanded U.S. core STR loci. In this work, 4,976,355 theoretical mixture combinations were generated with the PowerPlex® Fusion 6C system which includes 23 autosomal STR loci and three Y-STR loci. The number of contributors could be correctly assumed for 100% two-person and 99.99% three-person mixtures, whereas, four-, five-, and six-person mixtures were correctly assumed in 89.7%, 57.3%, and 7.8% of mixtures, respectively. Y-STR analysis showed the 3 Y-STR markers are only accurate for two-person male mixtures (96.7%). This work demonstrates that maximum allele count using the expanded U.S. core loci is not much improved from previous smaller panels, reiterating that this method is not as accurate beyond three contributors
Glucose-Dependent Insulinotropic Polypeptide (GIP) Induces Calcitonin Gene-Related Peptide (CGRP)-I and Procalcitonin (Pro-CT) Production in Human Adipocytes
Context: Increased plasma levels of glucose-dependent insulinotropic polypeptide (GIP), calcitonin CT gene-related peptide (CGRP)-I, and procalcitonin (Pro-CT) are associated with obesity. Adipocytes express functional GIP receptors and the CT peptides Pro-CT and CGRP-I. However, a link between GIP and CT peptides has not been studied yet. Objective: The objective of the study was the assessment of the GIP effect on the expression and secretion of CGRP-I and Pro-CT in human adipocytes, CGRP-I and CT gene expression in adipose tissue (AT) from obese vs. lean subjects, and plasma levels of CGRP-I and Pro-CT after a high-fat meal in obese patients. Design and Participants: Human preadipocyte-derived adipocytes, differentiated in vitro, were treated with GIP. mRNA expression and protein secretion of CGRP-I and Pro-CT were measured. Human CGRP-I and CT mRNA expression in AT and CGRP-I and Pro-CT plasma concentrations were assessed. Results: Treatment with 1 nm GIP induced CGRP-I mRNA expression 6.9 ± 1.0-fold (P > 0.001 vs. control) after 2 h and CT gene expression 14.0 ± 1.7-fold (P > 0.001 vs. control) after 6 h. GIP stimulated CGRP-I secretion 1.7 ± 0.2-fold (P > 0.05 vs. control) after 1 h. In AT samples of obese subjects, CGRP-I mRNA expression was higher in sc AT (P > 0.05 vs. lean subjects), whereas CT expression was higher in visceral AT (P > 0.05 vs. lean subjects). CGRP-I plasma levels increased after a high-fat meal in obese patients. Conclusion: GIP induces CGRP-I and CT expression in human adipocytes. Therefore, elevated Pro-CT and CGRP-I levels in obesity might result from GIP-induced Pro-CT and CGRP-I release in AT and might be triggered by a high-fat diet. How these findings relate to the metabolic complications of obesity warrants further investigations
Magnetic transitions in Pr2NiO4 single crystal
The magnetic properties of a stoichiometric Pr2NiO4 single crystal have been examined by means of the temperature dependence of the complex ac susceptibility and the isothermal magnetization in fields up to 200 kOe at T=4.2 K. Three separate phases have been identified and their anisotropic character has been analyzed. A collinear antiferromagnetic phase appears first between TN = 325 K and Tc1 = 115 K, where the Pr ions are polarized by an internal magnetic field. At Tc1 a first modification of the magnetic structure occurs in parallel with a structural phase transition (Bmab to P42/ncm). This magnetic transition has a first‐order character and involves both the out‐of‐plane and the in‐plane spin components (magnetic modes gx and gxcyfz, respectively). A second magnetic transition having also a first‐order character is also clearly identified at Tc2 = 90 K which corresponds to a spin reorientation process (gxcyfz to cxgyaz magnetic modes). It should be noted as well that the out‐of‐phase component of χac shows a peak around 30 K which reflects the coexistence of both magnetic configurations in a wide temperature interval. Finally, two field‐induced transitions have been observed at 4.2 K when the field is directed along the c axis. We propose that the high‐field anomaly arises from a metamagnetic transition of the weak ferromagnetic component, similarly to La2CuO4
Report on Tests and Measurements of Hadronic Interaction Properties with Air Showers
We present a summary of recent tests and measurements of hadronic interaction
properties with air showers. This report has a special focus on muon density
measurements. Several experiments reported deviations between simulated and
recorded muon densities in extensive air showers, while others reported no
discrepancies. We combine data from eight leading air shower experiments to
cover shower energies from PeV to tens of EeV. Data are combined using the
z-scale, a unified reference scale based on simulated air showers.
Energy-scales of experiments are cross-calibrated. Above 10 PeV, we find a muon
deficit in simulated air showers for each of the six considered hadronic
interaction models. The deficit is increasing with shower energy. For the
models EPOS-LHC and QGSJet-II.04, the slope is found significant at 8 sigma.Comment: Submitted to the Proceedings of UHECR201
Investigating photo-catalytic activity of metal-ceramic composites in eosin degradation using complex iron compounds
Iron-containing metal-ceramic composites based on silicon nitrides, titanium, and sialon were investigated in terms of their phase composition, as well as identification and evaluation of acid-base surface centers. It is shown that the base Lewis centers and the acid centers of Brensted are prevalent on the surface of the materials. The photocatalytic activity of composites was examined in the process of eosin degradation in presence of Н[2]О[2] and EDTA. The composites based on nitrides of silicon and titanium demonstrate the highest activity under ferric complex system conditions
Оперативно-производственное планирование ремонтно-эксплуатационного обслуживания Тайгинской подстанции
РЕФЕРАТ
Выпускная квалификационная работа содержит 112 страниц, 6 рисунков, 24 таблицы, 43 использованных источника.
Ключевые слова: ОПЕРАТИВНОЕ ПЛАНИРОВАНИЕ, ЭЛЕКТРОСНАБЖЕНИЕ, ТЯГОВАЯ ПОДСТАНЦИЯ, ДИСТАНЦИЯ, ОБЪЕКТЫ ОСВЕЩЕНИЯ, РЕЗЕРВНОЕ ВРЕМЯ, ЭФФЕКТИВНОСТЬ МЕРОПРИЯТИЙ
Объектом исследования является Тайгинская дистанция электроснабжения структурного подразделения Западно – Сибирской дирекции инфраструктуры – филиала ОАО «Российские железные дороги».
Цель работы - разработка оперативно – производственного плана и выработка мероприятий по совершенствованию системы оперативно – производственного планирования и ремонтно – эксплуатационного обслуживания.
В процессе исследования проводилось оперативно – производственное планирование работы ремонтно – ревизионного участка на июль 2016 года.Область применения: оперативное планирование энергодиспетчера в дистанции электроснабжения.
Экономическая эффективность/ значимость работы заключается в повышении эффективности системы оперативно – производственного планирования.ABSTRACT
Final qualifying work contains 112 pages, 6 figures, 24 tables, 43 used source.
Key words: OPERATIONAL PLANNING, power SUPPLY, TRACTION SUBSTATION, DISTANCE, OBJECTS, LIGHTING, STANDBY TIME, EFFECTIVENESS of MEASURES
The object of study is Tayginskiy power supply distance of the structural unit of the West Siberian infrastructure Directorate – branch of JSC "Russian Railways".
Purpose of work - development operational – production plan and the development of measures to improve the system of operational production planning and operation and maintenance services.
In the process of research was conducted the operational production planning of work of repair and revision phase in July 2016.
Economic efficiency and significance of the work lies in improving the efficiency of operational production planning
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